MPI <4G1> -
Troubleshooting
13A-59
INSPECTION PROCEDURE 24
Check the engine-ECU power supply and earth circuit.
Measure the engine-ECU connectors, B-34, B-36, B-37.
D
Disconnect the connector and measure at the harness side
1. Voltage between 82 and earth (Ignition switch: ON)
OK:
System voltage
2. Voltage between 38 and earth
OK:
System voltage
3. Voltage between 12, 25 and earth (Ignition switch: ON)
OK:
System voltage (when the terminal 38 is earthed)
4. Continuity between 13, 26 and earth
OK:
Continuity
5. Voltage between 80 and earth
OK:
System voltage
1. NG
Check the following
connectors:
B-32, B-70
NG
Repair
OK
Check the trouble symptom.
OK
Check the harness wire
between engine-ECU and
ignition switch connector.
NG
Repair
OK
Check the ignition switch.
(Refer to GROUP 54 - Ignition Switch and Immobilizer System.)
2., 3. NG
Check the following
connectors:
B-36, B-37
NG
Repair
OK
Check the trouble symptoms.
NG
Check the harness wire between engine-ECU and control relay
connector, and repair if necessary.
4. NG
Check the harness wire between engine-ECU and earth, and repair
if necessary.
5. NG
OK
Check the following
connectors:
B-34, B-36, B-37
NG
Repair
OK
Check the trouble symptom.
NG
Replace the engine-ECU.
Check the following connectors:
B-32, B-34, B-48, B-62, B-69
NG
Repair
OK
Check the trouble symptom.
NG
Check the harness wire between engine-ECU and battery, and
repair if necessary.
INSPECTION PROCEDURE 25
Power supply system and ignition switch-IG system
Probable cause
When an ignition switch ON signal is input to the engine-ECU, the engine-ECU turns
the control relay ON. This causes battery voltage to be supplied to the engine-ECU,
injectors and air flow sensor.
D
Malfunction of the ignition switch
D
Malfunction of the control relay
D
Improper connector contact, open circuit or
short-circuited harness wire
D
Disconnected engine-ECU earth wire
D
Malfunction of the engine-ECU
Check the control relay. (Refer to P.13A-83*.)
NG
Replace
OK
Measure at the control relay connector B-13.
D
Disconnect the connector, and measure at the harness side.
D
Voltage between 3, 4 and earth
OK:
System voltage
NG
Check the following
connector:
A-10
NG
Repair
OK
Check the trouble symptom.
NG
Check theharness wire between battery and control relay connector,
and repair if necessary.
OK
Check the engine-ECU power supply and earth circuit.
(Refer to P.13A-59, INSPECTION PROCEDURE 24.)
NOTE:
*: Refer to the ’96 COLT/LANCER Workshop Manual (Pub. No. PWME9511).